From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933390AbbAIK5S (ORCPT ); Fri, 9 Jan 2015 05:57:18 -0500 Received: from cantor2.suse.de ([195.135.220.15]:60509 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932333AbbAIK5Q (ORCPT ); Fri, 9 Jan 2015 05:57:16 -0500 Date: Fri, 9 Jan 2015 10:57:10 +0000 From: Mel Gorman To: Vlastimil Babka Cc: Joonsoo Kim , Andrew Morton , David Rientjes , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/3] mm/compaction: enhance trace output to know more about compaction internals Message-ID: <20150109105710.GN2395@suse.de> References: <1417593127-6819-1-git-send-email-iamjoonsoo.kim@lge.com> <54ABA563.1040103@suse.cz> <20150108081835.GC25453@js1304-P5Q-DELUXE> <54AE43E3.60209@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <54AE43E3.60209@suse.cz> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 08, 2015 at 09:46:27AM +0100, Vlastimil Babka wrote: > On 01/08/2015 09:18 AM, Joonsoo Kim wrote: > > On Tue, Jan 06, 2015 at 10:05:39AM +0100, Vlastimil Babka wrote: > >> On 12/03/2014 08:52 AM, Joonsoo Kim wrote: > >> > It'd be useful to know where the both scanner is start. And, it also be > >> > useful to know current range where compaction work. It will help to find > >> > odd behaviour or problem on compaction. > >> > >> Overall it looks good, just two questions: > >> 1) Why change the pfn output to hexadecimal with different printf layout and > >> change the variable names and? Is it that better to warrant people having to > >> potentially modify their scripts parsing the old output? > > > > Deciaml output has really bad readability since we manage all pages by order > > of 2 which is well represented by hexadecimal. With hex output, we can > > easily notice whether we move out from one pageblock to another one. > > OK. I don't have any strong objection, maybe Mel should comment on this as the > author of most of the tracepoints? But if it happens, I think converting the old > tracepoints to new hexadecimal format should be a separate patch from adding the > new ones. > To date, I'm not aware of any user-space programs that heavily depend on the formatting. The scripts I am aware of are ad-hoc and easily modified to adapt to format changes. LTT-NG is the only tool that might be depending on trace point formats but I severely doubt it's interested in this particular tracepoint. -- Mel Gorman SUSE Labs